1. Technical Field
The present disclosure is related to a wireless power transmission apparatus and a wireless power transmission system including the wireless power transmission apparatus contactlessly transmitting electric power by using electromagnetic induction between a transmission coil and a power reception coil.
2. Description of the Related Art
In recent years, a portable telephone apparatus and other various kinds of mobile devices have become popular. In such mobile devices, an improvement in function and performance has been made and it has become possible to treat a wide variety of contents, and accordingly the mobile devices need increasingly large power consumption. In a mobile device that operates with a battery with a predetermined capacity, if the power consumption thereof increases, the allowed operation time thereof decreases. A wireless power transmission system is attracting much attention as a technique to compensate for the above-described limitation on the capacity of the battery. In the wireless power transmission system, electric power is transmitted contactlessly from a wireless power transmission apparatus to a wireless power reception apparatus by using electromagnetic induction between a transmission coil of the wireless power transmission apparatus and a power reception coil of the wireless power reception apparatus. In particular, a wireless power transmission system using a resonant transmission coil and a resonant power reception coil (resonant magnetic coupling) is capable of maintaining a high transmission efficiency even when there is some deviation in relative position between the transmission coil and the power reception coil, and thus this type of wireless power transmission system is expected to be used in various applications.
Descriptions on related techniques may be found, for example, Japanese Unexamined Patent Application Publication No. 2010-016985, International Publication No. 2012/081519, and International Publication No. 2012/164744.